JPH10242771A - Linearization method for amplifier using improved feedforward correction - Google Patents
Linearization method for amplifier using improved feedforward correctionInfo
- Publication number
- JPH10242771A JPH10242771A JP10036888A JP3688898A JPH10242771A JP H10242771 A JPH10242771 A JP H10242771A JP 10036888 A JP10036888 A JP 10036888A JP 3688898 A JP3688898 A JP 3688898A JP H10242771 A JPH10242771 A JP H10242771A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- amplifier
- output
- preamplifier
- power amplifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3223—Modifications of amplifiers to reduce non-linear distortion using feed-forward
- H03F1/3229—Modifications of amplifiers to reduce non-linear distortion using feed-forward using a loop for error extraction and another loop for error subtraction
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/198—A hybrid coupler being used as coupling circuit between stages of an amplifier circuit
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2201/00—Indexing scheme relating to details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements covered by H03F1/00
- H03F2201/32—Indexing scheme relating to modifications of amplifiers to reduce non-linear distortion
- H03F2201/3212—Using a control circuit to adjust amplitude and phase of a signal in a signal path
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2201/00—Indexing scheme relating to details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements covered by H03F1/00
- H03F2201/32—Indexing scheme relating to modifications of amplifiers to reduce non-linear distortion
- H03F2201/3221—Predistortion by overamplifying in a feedforward stage the distortion signal to have a combined main signal and "negative" distortion to form the predistorted signal for a further stage. so that after amplification in the further stage only the amplified main signal remains
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Amplifiers (AREA)
Abstract
Description
【０００１】[0001]
【産業の利用分野】本発明は、改良フィ−ドフォワ−ド
補正を利用する増幅器の直線化に関する。This invention relates to amplifier linearization utilizing improved feedforward correction.
【０００２】[0002]
【従来の技術】非線形信号応答特性を補正する増幅手段
のフィ−ドフォワ−ド補正は、サビンら（W.E. Sabin a
nd E.O. Schoenike, McGraw-Hill, Inc. 1987)によって
編集された題名“単側波帯システンムおよび回路”なる
刊行物の第４４８−４７２頁、第１３章に見られるシラ
ギ（Edward G. Silagi) による題名“超低ひずみ電力増
幅器”の論文から知られている。フィ−ドフォワ−ド補
正は、典型的に増幅器への入力信号のサンプルを得て、
それと増幅器の出力から取ったサンプルと比較して誤り
信号を得ることを含む。その誤り信号は増幅器の非線形
信号応答特性（ノイズおよびひずみ）を示す。この誤り
信号は次に出力信号を入力信号と直線的に関係させる方
向に増幅器の出力信号と組み合わされる。増幅器のフィ
−ドフォワ−ド補正を開示する他の文献は次の米国特許
第３、４７１、７９８号、第４、３４８、６４２号、第
４、３５２、０７２号および第４、５９５、８８２号の
明細書に記載のものを含む。2. Description of the Related Art Feedforward correction of amplifying means for correcting a non-linear signal response characteristic is performed by WE Sabin et al.
ed EO Schoenike, McGraw-Hill, Inc. 1987) by Edward G. Silagi in the publication entitled "Single Sideband Systems and Circuits", pages 448-472, Chapter 13. It is known from the paper entitled "Ultra Low Distortion Power Amplifier". Feedforward correction typically involves taking samples of the input signal to the amplifier,
And comparing it with a sample taken from the output of the amplifier to obtain an error signal. The error signal indicates the nonlinear signal response characteristics (noise and distortion) of the amplifier. This error signal is then combined with the output signal of the amplifier in a direction that makes the output signal linearly related to the input signal. Other references disclosing amplifier feedforward correction are U.S. Pat. Nos. 3,471,798, 4,348,642, 4,352,072 and 4,595,882. Including those described in the specification.
【０００３】[0003]
【発明が解決しようとする課題】増幅器の上記フィ−ド
フォワ−ド補正は、その増幅器の非線形特性を補正する
機能を果たすが、後続増幅器又は出力増幅器の非線形信
号応答特性の改善をしない。この後続の増幅器は補正を
必要とする非線形信号応答特性を有する。また、出力増
幅器が高電力レベルで作動する場合、フィ−ドフォワ−
ド補正は典型的に電力の１／４〜１／２以上の損失をも
たらすので、出力増幅器でフィ−ドフォワ−ド補正を利
用するのは経済的でない。本発明の目的は、先行増幅器
にフィ−ドフォワ−ド過補正を提供することによって非
線形信号応答特性を有する出力増幅器の直線性を改善す
ることにある。The above-described feedforward correction of an amplifier serves to correct the nonlinear characteristics of the amplifier, but does not improve the nonlinear signal response characteristics of the subsequent amplifier or output amplifier. This subsequent amplifier has a non-linear signal response that requires correction. Also, if the output amplifier operates at a high power level, the feedforward
Utilizing feedforward correction in the output amplifier is not economical, as the field correction typically results in a loss of 1/4 to 1/2 or more of the power. SUMMARY OF THE INVENTION It is an object of the present invention to improve the linearity of an output amplifier having a non-linear signal response by providing feedforward overcorrection to the preceding amplifier.
【０００４】[0004]
【課題を解決するための手段】本発明により、非線形信
号応答特性を有し信号源と負荷の間の多段増幅器網に配
置された出力増幅器が、先行する増幅器にフィ−ドフォ
ワ−ド補正を提供することによって線形化される。これ
は、多段増幅器網内にあって出力増幅器の非線形信号応
答特性に類似する非線形信号応答特性を示す先行増幅器
を選択することによって達成される。入力信号は選択さ
れた増幅器に印加されて、選択された先行増幅器の非線
形信号応答特性の関数として入力信号と異なる信号差を
有する中間出力信号を発生する。その入力信号の少なく
とも一部と中間出力信号の少なくとも一部が組み合わさ
れて、信号差を表す誤り信号が得られる。その誤り信号
と中間出力信号を組み合わせて補正された中間出力信号
が得られる。補正された中間出力信号は出力増幅器に印
加されて出力信号が得られる。その誤り信号は、出力増
幅器の非線形信号応答特性を補償するのに十分な量まで
過補正された過補正中間出力信号を提供する方向に調節
され、それによって出力増幅器からの出力信号は本質的
に入力信号に直線的に関係することになる。SUMMARY OF THE INVENTION In accordance with the present invention, an output amplifier having a non-linear signal response and located in a multistage amplifier network between a signal source and a load provides feedforward correction to a preceding amplifier. Is linearized. This is achieved by selecting a leading amplifier in the multistage amplifier network that exhibits a non-linear signal response similar to that of the output amplifier. The input signal is applied to the selected amplifier to produce an intermediate output signal having a signal difference that differs from the input signal as a function of the non-linear signal response characteristics of the selected preamplifier. At least a part of the input signal and at least a part of the intermediate output signal are combined to obtain an error signal representing a signal difference. A corrected intermediate output signal is obtained by combining the error signal and the intermediate output signal. The corrected intermediate output signal is applied to an output amplifier to obtain an output signal. The error signal is adjusted in a direction to provide an overcorrected intermediate output signal that is overcorrected by an amount sufficient to compensate for the nonlinear signal response characteristics of the output amplifier, whereby the output signal from the output amplifier is essentially reduced. It will be linearly related to the input signal.
【０００５】本発発明は、非線形信号応答特性を有し信
号源と負荷の間の多段増幅器網に配置された出力増幅手
段を、先行する増幅手段にフィ−ドフォワ−ド補正を提
供することによって線形化する方法において、前記多段
増幅器網内あって、前記出力増幅器の非線形信号応答特
性に類似する非線形信号応答特性を示す前記先行増幅手
段を選択する工程；該選択した先行増幅手段に入力信号
を印加して、該選択した先行増幅手段の非線形信号応答
特性の関数として通常前記入力信号と異なる信号差を有
する中間出力信号を発生させる工程；前記入力信号の少
なくとも一部と前記中間出力信号の少なくとも一部を組
み合わせて、前記信号差を表す誤り信号を得る工程；前
記誤り信号と前記中間出力信号を組み合わせて補正され
た中間出力信号を得る工程；該補正された中間出力信号
を前記出力増幅手段に印加して出力信号を得る工程；お
よび前記出力増幅手段の非線形信号応答特性を補償する
のに十分な量まで過補正された該過補正中間出力信号を
提供する方向に前記誤り信号を調節する工程からなり；
それによって前記出力増幅手段からの前記出力信号を前
記入力信号に直線的に関係させることを特徴とする前記
出力増幅手段の線形化法を含む。The present invention provides an output amplifying means having a non-linear signal response characteristic and located in a multi-stage amplifier network between a signal source and a load, by providing feedforward correction to the preceding amplifying means. Selecting the preamplifier in the multi-stage amplifier network and exhibiting a non-linear signal response characteristic similar to the non-linear signal response characteristic of the output amplifier; applying an input signal to the selected preamplifier. Applying to generate an intermediate output signal having a signal difference that is typically different from the input signal as a function of the non-linear signal response characteristic of the selected preamplifier; at least a portion of the input signal and at least the intermediate output signal. Combining a part to obtain an error signal representing the signal difference; combining the error signal and the intermediate output signal to obtain a corrected intermediate output signal; Applying the corrected intermediate output signal to the output amplifying means to obtain an output signal; and overcorrecting the overcorrected amount to an amount sufficient to compensate for a nonlinear signal response characteristic of the output amplifying means. Adjusting the error signal in a direction to provide a corrected intermediate output signal;
Thereby, the output signal from the output amplifying means is linearly related to the input signal.
【０００６】添付図面を参照して、実施例によって以下
に本発明を記載する。The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
【０００７】[0007]
【実施例】本発明は、非線形信号応答特性を有し信号源
と負荷間の多段増幅器網に配置される出力増幅器の直線
化に関する。その直線化は先行増幅器にフィ−ドフォワ
−ド過補正を与えることによって達成される。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the linearization of an output amplifier having a non-linear signal response and located in a multi-stage amplifier network between a signal source and a load. The linearization is achieved by providing feedforward overcorrection to the preamplifier.
【０００８】図１に示した増幅器網には、電力増幅器の
形態をとる出力増幅器ＰＡと、ここでは中間電力増幅器
と呼ぶ先行増幅器ＩＰＡがある。これらの増幅器は増幅
器網において直列に接続され、信号源ＳＳと負荷（アン
テナ１０として示す）の間に配置されている。その出力
増幅器は完全に最終段階である必要はなく、中間電力増
幅器ＩＰＡのような中間増幅器にできるし、出力増幅器
ＰＡはアンテナ１０と共に負荷と考えられる。図４に関
して、後で詳述するように、本発明の別のバ−ジョン
は、増幅器網においてより低い電力段階に配置の中間周
波数増幅器を利用することを包含する。その実施例にお
ける出力増幅器は中間電力増幅器ＩＰＡ，出力増幅器Ｐ
Ａおよびアンテナ１０と考えられる。In the amplifier network shown in FIG. 1, there is an output amplifier PA in the form of a power amplifier and a preceding amplifier IPA, here called an intermediate power amplifier. These amplifiers are connected in series in an amplifier network and are arranged between a signal source SS and a load (shown as antenna 10). The output amplifier need not be completely final, it can be an intermediate amplifier, such as an intermediate power amplifier IPA, and the output amplifier PA, along with the antenna 10, is considered a load. With reference to FIG. 4, another version of the present invention involves utilizing an intermediate frequency amplifier located at a lower power stage in the amplifier network, as will be described in greater detail below. The output amplifier in the embodiment is an intermediate power amplifier IPA and an output amplifier P
A and antenna 10.
【０００９】その方法は、テレビ送信機における線形増
幅の改善に用いられる。かかる他の状態は、例えば、単
側波帯通信送信機、セル方式のラジオ・ベ−スステ−シ
ョン送信機、およびマイクロ波送信機を含む。[0009] The method is used to improve linear amplification in television transmitters. Such other states include, for example, single sideband communication transmitters, cellular radio base station transmitters, and microwave transmitters.
【００１０】図１、図２、および図３の実施例におい
て、出力電力増幅器ＰＡの直線性は、中間電力増幅器Ｉ
ＰＡの周囲にフィ−ドフォワ−ド回路を設けることによ
って補正される。In the embodiments of FIGS. 1, 2 and 3, the linearity of the output power amplifier PA is
This is corrected by providing a feedforward circuit around the PA.
【００１１】図１に示すような複数の増幅器を有する回
路網において、中間電力増幅器ＩＰＡのような先行増幅
器は、それが出力電力増幅器ＰＡに類似する非線形信号
応答特性を示すように選ぶ。即ち、曲線２０はフィ−ド
フォワ−ド補正を加える前のＩＰＡ伝達曲線を示す。こ
の曲線は、非線形であって、出力信号が印加入力信号に
非線形に応答することがわかる。曲線２２は、フィ−ド
フォワ−ド補正後に入力に対する出力の直線関係を提供
するＩＰＡ伝達曲線を示す。出力増幅器ＰＡは中間電力
増幅器ＩＰＡに対して曲線２０に類似する非線形信号応
答特性を有する。選択した増幅器ＩＰＡもＩＰＡ伝達曲
線によって立証される非線形信号応答特性を示す。本発
明は、過補正後にＩＰＡ伝達曲線を示す曲線２４によっ
て示されるように過補正が得られるようにフィ−ドフォ
ワ−ド補正を調節することを意図している。In a network having a plurality of amplifiers as shown in FIG. 1, a leading amplifier, such as an intermediate power amplifier IPA, is chosen such that it exhibits a non-linear signal response similar to the output power amplifier PA. That is, curve 20 shows the IPA transfer curve before the feedforward correction is applied. It can be seen that this curve is non-linear and the output signal responds non-linearly to the applied input signal. Curve 22 shows the IPA transfer curve which provides the linear relationship of input to output after feedforward correction. Output amplifier PA has a non-linear signal response characteristic similar to curve 20 for intermediate power amplifier IPA. The selected amplifier IPA also exhibits a non-linear signal response as evidenced by the IPA transfer curve. The present invention contemplates adjusting the feedforward correction so that overcorrection is obtained as shown by curve 24, which shows the IPA transfer curve after overcorrection.
【００１２】図１から、入力信号のサンプルを提供し、
それを増幅器３４と可変遅延回路３６によって混成結合
器３２の入力へ印加する方向性結合器３０をフィ−ドフ
ォワ−ドが含むことがわかる。中間電力増幅器ＩＰＡの
出力信号のサンプルが可変方向性結合器４０で得られ
て、結合器３２の入力ｂへ送られる。その結合器はその
入力ａおよびｂに印加される信号を結合して、出力ｃに
信号のベクトル差、そして出力ｄ（それはダミ−負荷抵
抗器３８で終わる）に入力のベクトル和を提供する。From FIG. 1, providing samples of the input signal,
It can be seen that the feedforward includes a directional coupler 30 which applies it to the input of hybrid coupler 32 by amplifier 34 and variable delay circuit 36. Samples of the output signal of the intermediate power amplifier IPA are obtained at the variable directional coupler 40 and sent to the input b of the coupler 32. The combiner combines the signals applied to its inputs a and b to provide the vector difference of the signal at output c, and the vector sum of the inputs at output d, which terminates at the dummy-load resistor 38.
【００１３】可変遅延回路３６は、中間電力増幅器ＩＰ
Ａを介して遅延を補償するように調節できる。これによ
って、入力信号のサンプルおよび出力信号のサンプルを
結合器の入力に整合したタイミングで到達させることが
できる。方向性結合器４０の結合係数Ｋ２は、公称小信
号条件下で２つのサンプル入力が等しく同位相であるよ
うに調節される。方向性結合器４０は中間電力増幅器Ｉ
ＰＡの出力信号の大きさを変えるために利用するが、可
変遅延回路３６は２つのサンプルの遅延関係を変えるた
めに利用する。それらのサンプルが同一であると、出力
端子ｃにおける Ｋ１＝（Ｇ１）（Ｋ２） （１） 但しＧ１は中間電力増幅器ＩＰＡの利得を表し、Ｋ１は
方向性結合器３０の結合係数を表す。The variable delay circuit 36 includes an intermediate power amplifier IP
A can be adjusted to compensate for the delay via A. Thereby, the sample of the input signal and the sample of the output signal can arrive at the timing matched with the input of the combiner. The coupling coefficient K2 of the directional coupler 40 is adjusted so that the two sample inputs are equal and in phase under nominal small signal conditions. The directional coupler 40 is an intermediate power amplifier I
The variable delay circuit 36 is used to change the magnitude of the output signal of the PA, while the variable delay circuit 36 is used to change the delay relationship between the two samples. If the samples are the same, K1 at the output terminal c = (G1) (K2) (1) where G1 represents the gain of the intermediate power amplifier IPA and K1 represents the coupling coefficient of the directional coupler 30.
【００１４】さらに大きい信号条件下では、中間電力増
幅器ＩＰＡの利得（Ｇ１）は変わり、混成結合器３２の
出力ｃに誤り信号が現れる。この誤り信号は可変遅延回
路５０と可変減衰器５２で調節され、線形増幅器５４で
増幅されて、方向性結合器５６により中間電力増幅器の
出力信号と組み合わされる。可変遅延回路５０は、遅延
回路５０、減衰器５２および増幅器５４を含む補正路を
介した遅延が中間電力増幅器ＩＰＡの出力回路における
パスに整合するように調節される、そしてこれは固定遅
延回路５８を含む。Under larger signal conditions, the gain (G1) of the intermediate power amplifier IPA changes and an error signal appears at the output c of the hybrid combiner 32. This error signal is adjusted by the variable delay circuit 50 and the variable attenuator 52, amplified by the linear amplifier 54, and combined with the output signal of the intermediate power amplifier by the directional coupler 56. Variable delay circuit 50 is adjusted so that the delay through the correction path including delay circuit 50, attenuator 52 and amplifier 54 matches the path in the output circuit of intermediate power amplifier IPA, which is a fixed delay circuit 58. including.
【００１５】可変減衰器５２は通常、方向性結合器５
０、混成結合器３２、線形増幅器５４および結合器５６
介した中間電力増幅器ＩＰＡの出力からの利得が１とな
るように調節される。即ち、次式に従う： （Ｋ２）（Ｇ２）（Ｋ３）＝１ （２） ここで利得Ｇ２は線形増幅器５４の利得であり、Ｋ３は
方向性結合器５６の結合係数である。線形増幅器の利得
Ｇ２は混成結合器３２および可変減衰器５２における損
失を含むようにとる。The variable attenuator 52 usually has a directional coupler 5.
0, hybrid combiner 32, linear amplifier 54 and combiner 56
The gain from the output of the intermediate power amplifier IPA is adjusted to be unity. That is, according to the following equation: (K2) (G2) (K3) = 1 (2) where G2 is the gain of the linear amplifier 54 and K3 is the coupling coefficient of the directional coupler 56. The gain G2 of the linear amplifier is set to include the loss in the hybrid coupler 32 and the variable attenuator 52.
【００１６】フィ−ドフォワ−ド信号は中間電力増幅器
ＩＰＡにおける非直線性を補正する作用をする。これは
図２に曲線２０が補正前のＩＰＡ伝達曲線を表すること
を記すことによって示される。曲線２２はフィ−ドフォ
ワ−ド補正後のＩＰＡ伝達曲線を示す。これは入力に関
して中間電力増幅器ＩＰＡの出力の直線関係にある。適
当に調節することによって、いずれの大きさの非直線性
も完全に補正される。いずれの位相の非直線性も実質的
に補正される。この意味で、位相非直線性は、入力信号
のレベルの関数として中間電力増幅器ＩＰＡを介した移
相における変動と定義される。The feedforward signal serves to correct for non-linearities in the intermediate power amplifier IPA. This is shown in FIG. 2 by noting that curve 20 represents the uncorrected IPA transfer curve. Curve 22 shows the IPA transfer curve after the feedforward correction. This is a linear relationship of the output of the intermediate power amplifier IPA with respect to the input. With appropriate adjustments, any magnitude of non-linearity is completely corrected. Any phase non-linearities are substantially corrected. In this sense, phase nonlinearity is defined as the variation in phase shift through the intermediate power amplifier IPA as a function of the level of the input signal.
【００１７】フィ−ドフォワ−ド補正は、得られる出力
信号が入力信号に対して実質的に直線関係を示すように
中間電力増幅器ＩＰＡの補正をする。しかしながら、こ
れは、電力増幅器ＰＡの形態をとる出力増幅器の非線形
信号応答特性を補償する補正を提供しなかった。本発明
によって、電力増幅器ＰＡの伝達特性における非線形は
中間電力増幅器ＩＰＡのフィ−ドフォワ−ド過補正によ
って補正される。中間電力増幅器ＩＰＡは電力増幅器Ｐ
Ａに類似する非線形信号応答特性を示すように選ぶ。し
たがって、電力増幅器ＰＡの伝達曲線特性が中間電力増
幅器ＩＰＡの伝達曲線特性に類似する場合には、電力増
幅器ＰＡの非線形信号応答特性は減衰器５２を調節する
ことによって実質的に補正することができる。例えば、
減衰器５２は中間電力増幅器ＩＰＡの完全補正用より６
ｄＢ低い値をもつように調節する。この場合に、方向性
結合器５６を介して導入される補正信号は、中間電力増
幅器ＩＰＡを補正するのに必要な値より電圧を基準にし
て２倍大きい。追加の補正量は電力増幅器ＰＡの非線形
特性を補正するのに適当な大きさである。これは、補正
前の中間電力増幅器ＩＰＡと電力増幅器ＰＡの両方を組
み合わせた伝達曲線を示す伝達曲線６０を示す図３を参
照することによってわかる。中間電力増幅器ＩＰＡに過
補正をした後の組み合わせ伝達曲線は、中間電力増幅器
ＩＰＡへの入力に対する電力増幅器ＰＡ出力の線形応答
を与える図３の曲線６２で示す。電力増幅器ＰＡにおけ
る位相非線形はこの操作によって実質的に補正される。The feedforward correction corrects the intermediate power amplifier IPA so that the resulting output signal has a substantially linear relationship with the input signal. However, this did not provide a correction to compensate for the non-linear signal response of the output amplifier in the form of a power amplifier PA. According to the present invention, the non-linearity in the transfer characteristic of the power amplifier PA is corrected by the feedforward overcorrection of the intermediate power amplifier IPA. The intermediate power amplifier IPA is the power amplifier P
A is selected to exhibit a non-linear signal response characteristic similar to A. Therefore, if the transfer curve characteristics of the power amplifier PA are similar to the transfer curve characteristics of the intermediate power amplifier IPA, the nonlinear signal response characteristics of the power amplifier PA can be substantially corrected by adjusting the attenuator 52. . For example,
The attenuator 52 is more than 6% for complete correction of the intermediate power amplifier IPA.
Adjust to have a dB lower value. In this case, the correction signal introduced via the directional coupler 56 is twice as large on a voltage basis as is necessary to correct the intermediate power amplifier IPA. The additional correction amount is a magnitude suitable for correcting the non-linear characteristic of the power amplifier PA. This can be seen by referring to FIG. 3, which shows a transfer curve 60 showing a transfer curve combining both the intermediate power amplifier IPA and the power amplifier PA before correction. The combined transfer curve after overcorrection of the intermediate power amplifier IPA is shown by curve 62 in FIG. 3 giving the linear response of the power amplifier PA output to the input to the intermediate power amplifier IPA. The phase nonlinearity in the power amplifier PA is substantially corrected by this operation.
【００１８】選んだ中間電力増幅器ＩＰＡの非線形信号
応答特性は電力増幅器ＰＡの非線形信号応答特性と同一
であることが望ましいが、かかる整合はこの操作には必
要ない。出力増幅器の直線性の実質的な改善は、その伝
達曲線の大体の形状だけがフィ−ドフォワ−ド過補正を
する先行の増幅器の伝達曲線の形状に類似するならば得
られる。可変減衰器５２と可変遅延回路５０の両方を調
節して入力電力増幅器の非直線性またはひずみを最小に
することができる。例えば、単側波帯通信送信機におい
て、２つの音試験信号を用いて、可変遅延回路５０と可
変減衰器５２の調節をして、その結果をスペクトル分析
装置で観察する。ＨＤＴＶデジタル送信機における試験
信号は標準の８レベルＶＳＢ信号である。電力増幅器か
らの出力はスペクトル分析装置で観察して、可変減衰器
５２と可変遅延回路５０の調節をしてＦＣＣスペクトル
・マスク内の隣接チャネル干渉をさせる。It is desirable that the nonlinear signal response of the selected intermediate power amplifier IPA be the same as the nonlinear signal response of the power amplifier PA, but such matching is not required for this operation. A substantial improvement in the linearity of the output amplifier is obtained if only the approximate shape of its transfer curve is similar to the shape of the transfer curve of the preceding amplifier with feedforward overcorrection. Both the variable attenuator 52 and the variable delay circuit 50 can be adjusted to minimize the non-linearity or distortion of the input power amplifier. For example, in a single sideband communication transmitter, the variable delay circuit 50 and the variable attenuator 52 are adjusted using two sound test signals, and the result is observed by a spectrum analyzer. The test signal in an HDTV digital transmitter is a standard 8-level VSB signal. The output from the power amplifier is monitored by a spectrum analyzer and the variable attenuator 52 and variable delay circuit 50 are adjusted to cause adjacent channel interference in the FCC spectral mask.
【００１９】米国で使用されているような従来のアナロ
グテレビ送信機において、音声搬送波を含む標準ＮＴＳ
Ｃ信号は、重疂彩度をもったランプによって変調されて
増幅器ＩＰＡとＰＡの組合せ回路へ印加される。得られ
たスペクトルは分析装置で観察する。そのような場合、
視覚搬送波以下の０．９２ｍＨｚ（音声および彩度搬送
波間の差）と音声搬送波以上の０．９２ｍＨｚに観察さ
れる帯域外相互変調積がある。これらの相互変調積を最
小にするために、遅延回路５０と減衰器５２を調節す
る。In conventional analog television transmitters, such as those used in the United States, standard NTS including audio carriers
The C signal is modulated by a lamp having multiple saturations and applied to a combinational circuit of amplifiers IPA and PA. The obtained spectrum is observed with an analyzer. In such a case,
There is an out-of-band intermodulation product observed at 0.92 mHz below the visual carrier (difference between speech and chroma carriers) and 0.92 mHz above the speech carrier. In order to minimize these intermodulation products, the delay circuit 50 and the attenuator 52 are adjusted.
【００２０】要約すると、電力増幅器ＰＡのような出力
増幅器の線形化法は次の工程を含む。多段増幅器網にお
ける低電力増幅器ステ−ジを選ぶ、該選んだ増幅器ステ
−ジは、補正せんとする下流又は後続の増幅器ステ−ジ
に類似する非線形応答特性を示す。次に低電力増幅器ス
テ−ジにフィ−ドフォワ−ド補正を加える。混成結合器
３２への２つの入力の利得と位相は小信号条件に対して
整合される。これは遅延回路３６と方向性結合器４０を
調節することによって得られる。混成結合器３２の出力
ｃにおける出力信号が零又は最小のときに整合が得られ
る。次に、フィ−ドフォワ−ド補正信号が注入された後
にとった時点で増幅器ＩＰＡの出力をサンプリングす
る。これは、スペクトル分析装置でこの出力を観察する
ことによって得られる。フィ−ドフォワ−ド・ル−プに
おける利得および遅延を、電力増幅器ＰＡへの入力が中
間電力増幅器ＩＰＡへの入力に対して直線関係になるよ
うに調節する。低電力レベル・ステ−ジが補正される。
この時点で、電力増幅器の出力が、正常な信号条件下の
スペクトル分析装置の場合のように検討される。次に、
フィ−ドフォワ−ド・ル−プにおける利得および遅延
を、遅延回路５０および減衰器５２を調節するように再
調節して、電力増幅器ＰＡから得た出力が中間電力増幅
器ＩＰＡへ送られた入力に直線的に関係するように、電
力増幅器の入力に印加された信号を過補正する。In summary, a method for linearizing an output amplifier such as a power amplifier PA includes the following steps. Choosing a low power amplifier stage in a multi-stage amplifier network, the selected amplifier stage exhibits a non-linear response characteristic similar to the downstream or subsequent amplifier stage to be corrected. Next, feedforward correction is applied to the low power amplifier stage. The gain and phase of the two inputs to the hybrid combiner 32 are matched for small signal conditions. This is obtained by adjusting the delay circuit 36 and the directional coupler 40. Matching is obtained when the output signal at the output c of the hybrid combiner 32 is zero or minimum. Next, the output of the amplifier IPA is sampled at a point in time after the feedforward correction signal is injected. This is obtained by observing this output on a spectrum analyzer. The gain and delay in the feedforward loop are adjusted so that the input to power amplifier PA is linear with respect to the input to intermediate power amplifier IPA. The low power level stage is corrected.
At this point, the output of the power amplifier is considered as in a spectrum analyzer under normal signal conditions. next,
The gain and delay in the feedforward loop are readjusted to adjust delay circuit 50 and attenuator 52 so that the output from power amplifier PA is applied to the input sent to intermediate power amplifier IPA. Overcorrect the signal applied to the input of the power amplifier so that it is linearly related.
【００２１】図１に利用した回路の２、３のパラメ−タ
を以下に示す。図１に示した例は、高精細度テレビ（Ｈ
ＤＴＶ）に使用することを意図するもにであって、中間
電力増幅器への入力電力が０．０１Ｗの桁である。中間
電力増幅器の利得Ｇ１は、出力電力が４００Ｗの桁であ
るように４０、０００の桁である。方向性結合器３０の
結合係数Ｋ１は−２０ｄＢ又はＫ１＝１／１００の桁で
ある。方向性結合器４０の結合係数Ｋ２は−６６ｄＢ又
はＫ２＝１／４．０００，０００の桁である。中間電力
増幅器ＩＰＡの入力から出力の利得は＋４６ｄＢの桁で
ある。中間電力増幅器ＩＰＡは数増幅器ステ−ジであ
る。The following are a few parameters of the circuit used in FIG. The example shown in FIG. 1 is a high definition television (H
DTV), where the input power to the intermediate power amplifier is on the order of 0.01W. The gain G1 of the intermediate power amplifier is on the order of 40,000 such that the output power is on the order of 400W. The coupling coefficient K1 of the directional coupler 30 is in the order of -20 dB or K1 = 1/100. The coupling coefficient K2 of the directional coupler 40 is -66 dB or K2 = 1 / 4,000,000. The gain from input to output of the intermediate power amplifier IPA is of the order of +46 dB. The intermediate power amplifier IPA is a several amplifier stage.
【００２２】減衰器５２および結合器３２を含む線形増
幅器の利得Ｇ２は７２ｄＢの桁である。方向性結合器５
６用結合係数Ｋはの−６ｄＢ又はＫ３＝１／４の桁であ
る。中間電力増幅器ＩＰＡの出力から電力増幅器ＰＡの
入力への損失は、電力増幅器への入力が３００Ｗの桁で
あるように１００Ｗの桁である。電力増幅器は１００以
上の利得を有するので、電力増幅器の出力は４０、００
０Ｗの桁である。従って、電力増幅器にフィ−ドフォワ
−ド補正を提供するには、かかる高電力環境では極めて
コストがかかることになる。フィ−ドフォワ−ド損失は
入力信号の１／４〜１／２の桁であるので、かかる補正
は電力増幅器ステ−ジにおいて通常使用されない。The gain G2 of the linear amplifier including the attenuator 52 and the combiner 32 is on the order of 72 dB. Directional coupler 5
The coupling coefficient K for 6 is -6 dB or K3 = 1/4. The loss from the output of the intermediate power amplifier IPA to the input of the power amplifier PA is of the order of 100 W, as is the input to the power amplifier of the order of 300 W. Since the power amplifier has a gain of 100 or more, the output of the power amplifier is 40,00
It is a digit of 0W. Thus, providing feedforward correction to a power amplifier would be extremely costly in such high power environments. Such corrections are not typically used in power amplifier stages because feedforward losses are on the order of one quarter to one half of the input signal.
【００２３】図１の回路では増幅器３４は存在しないと
仮定する。その場合の方向性結合器は−２０ｄＢの利得
を有する。しかしながら、−３０〜−４０ｄＢの桁の大
きい結合係数を示す方向性結合器は作成が容易で安価で
ある。これは混成結合器３２へ供給されるサンプルの大
きさを小さくさせる。そのサンプルは結合器３０から遅
延回路３６までの回路に配置の増幅器３４でするように
増幅される。この増幅器は、結合係数Ｋ１と利得Ｇ３の
積が利得Ｇ１と結合係数Ｋ２の積と等しくなるような利
得Ｇ３を有する。In the circuit of FIG. 1, assume that amplifier 34 is not present. The directional coupler in that case has a gain of -20 dB. However, a directional coupler exhibiting a large coupling coefficient of the order of -30 to -40 dB is easy to manufacture and inexpensive. This reduces the size of the sample supplied to the hybrid coupler 32. The sample is amplified as by an amplifier 34 arranged in a circuit from the coupler 30 to the delay circuit 36. This amplifier has a gain G3 such that the product of the coupling coefficient K1 and the gain G3 is equal to the product of the gain G1 and the coupling coefficient K2.
【００２４】図１〜図３を参照してこれまでずっと検討
した改良フィ−ドフォワ−ド増幅器補正は、先行の中間
電力増幅器ＩＰＡにフィ−ドフォワ−ド過補正を提供す
ることによる電力増幅器ＰＡの非線形信号応答特性の補
償に関するものであった。これまで検討したように、こ
の改良フィ−ドフォワ−ド補正は、中間電力増幅器ＩＰ
Ａよりもさらに初期の低電力増幅器ステ−ジで行なわれ
る。The improved feedforward amplifier correction, which has been discussed with reference to FIGS. 1 to 3, is a power amplifier PA which provides a feedforward overcorrection to the preceding intermediate power amplifier IPA. It was about compensation for nonlinear signal response characteristics. As discussed above, this improved feedforward correction is based on the intermediate power amplifier IP
A is performed in an earlier low power amplifier stage than A.
【００２５】信号源ＳＳはいくつかの中間周波数ステ−
ジを含み、この場合のフィ−ドフォワ−ド補正は、これ
ら低電力中間周波数増幅器ステ−ジの１つ以上に過補正
を提供することによって利用される。これは、以下に説
明する。図１に対応又は類似する図４の構成部分は図１
においてプライム符号（´）を使用することによって類
似の数字のものと同一である。即ち、信号源は源ＳＳ´
である。図１の信号源ＳＳは図４の信号源ＳＳ´と中間
周波数増幅器ＩＦＡを含む。図１の可変結合器４０は図
４では固定方向性結合器１０２に代わり、振幅の調節を
提供する機能は結合器１０２と混成結合器３２´の端子
ｂへの入力間に配置の可変減衰器１０４によって提供さ
れる。この回路は、方向性結合器５６´と増幅器ＩＰＡ
間に配置のアップコンバ−タを含む。そのアップコンバ
−タは局部発信器１０８へ結合される。The signal source SS has several intermediate frequency stages.
In this case, feedforward correction is utilized by providing overcorrection to one or more of these low power intermediate frequency amplifier stages. This is described below. 4 corresponding to or similar to FIG.
Are identical to those of similar numbers by using the prime sign ('). That is, the signal source is the source SS '
It is. The signal source SS of FIG. 1 includes the signal source SS ′ of FIG. 4 and the intermediate frequency amplifier IFA. The variable coupler 40 of FIG. 1 replaces the fixed directional coupler 102 in FIG. 4, and the function of providing amplitude adjustment is a variable attenuator disposed between the coupler 102 and the input to terminal b of the hybrid coupler 32 '. 104. This circuit comprises a directional coupler 56 'and an amplifier IPA.
Includes an upconverter located in between. The upconverter is coupled to local oscillator 108.
【００２６】図４の中間周波数増幅器ＩＦＡは、中間電
力増幅器ＩＰＡおよび電力増幅器ＰＡの非線形信号特性
（位相および振幅）に類似の非線形信号特性を示すよう
に選ぶ。その方法は、出力増幅器がＩＰＡとＰＡの組合
せとみなされることを除いて、図１、図２および図３を
参照してこれまで記載したものと同一である。中間周波
数レベルにおける補正の方法は、電力レベルがｍＷの桁
のようにかなり低いので小型で低価格の構成部品をもた
らす。中間周波数増幅器ＩＦＡの設計には大きい融通性
があるので、その非線形信号応答特性は組み合わせた増
幅器ＩＰＡおよびＰＡの特性と整合する。The intermediate frequency amplifier IFA of FIG. 4 is selected so as to exhibit nonlinear signal characteristics similar to the nonlinear signal characteristics (phase and amplitude) of the intermediate power amplifier IPA and the power amplifier PA. The method is the same as that described above with reference to FIGS. 1, 2 and 3, except that the output amplifier is considered a combination of IPA and PA. The method of compensation at intermediate frequency levels results in small, low cost components because the power levels are much lower, on the order of mW. Because of the great flexibility in the design of the intermediate frequency amplifier IFA, its non-linear signal response matches that of the combined amplifiers IPA and PA.
【００２７】中間周波数レベルでのフィ−ドフォワ−ド
過補正の別の利点は、可変遅延回路５０´と可変減衰器
５２´が電子制御器で制御できることである。これはマ
イクロプロセッサをベ−スにしたシステムを使用して調
節を可能にする。Another advantage of feedforward overcorrection at intermediate frequency levels is that the variable delay circuit 50 'and the variable attenuator 52' can be controlled by an electronic controller. This allows for adjustment using a microprocessor based system.
【００２８】図５に示すように、図４の可変可変遅延回
路５０´と可変減衰器５２´がそれぞれ電子可変遅延回
路１５０と電子可変減衰器１５２と取り替えられてい
る。電子可変遅延回路１５０と電子可変減衰器１５２の
最適設定は異なる動作周波数で変わる。これは、動作周
波数が変わる送信機の場合に特に有用である。それらの
遅延回路と減衰器に適当な設定はマイクロプロセッサ１
５４のプログラマブルメモリに記憶される。このマイク
ロプロセッサは、使用する動作周波数を表す入力、デジ
タル周波数情報を受け入れて、選択した動作周波数に対
して電子可変遅延回路１５０と電子可変減衰器１５２を
調節するのに適当なデジタル制御信号を与える。かかる
放送送信機は異なる信号変調器を使用する。例えば、テ
レビジョン・サ−ビスにおいて、ＮＴＳＣアナログ信号
は昼間に送信され、ＨＤＴＶデジタル信号は夜間に送信
される。電子可変遅延回路１５０と電子可変減衰器１５
２に最適の設定はメモリに記憶されて、入力制御信号に
基づいてマイクロプロセッサに、又は信号特性の自動決
定に基づいて印加される。As shown in FIG. 5, the variable variable delay circuit 50 'and the variable attenuator 52' of FIG. 4 are replaced with an electronic variable delay circuit 150 and an electronic variable attenuator 152, respectively. The optimal settings of the electronic variable delay circuit 150 and the electronic variable attenuator 152 change at different operating frequencies. This is particularly useful for transmitters with varying operating frequencies. The appropriate settings for these delay circuits and attenuators are
It is stored in 54 programmable memories. The microprocessor accepts an input representing the operating frequency to be used, digital frequency information, and provides appropriate digital control signals to adjust the electronic variable delay circuit 150 and the electronic variable attenuator 152 for the selected operating frequency. . Such broadcast transmitters use different signal modulators. For example, in a television service, NTSC analog signals are transmitted during the day and HDTV digital signals are transmitted at night. Electronic variable delay circuit 150 and electronic variable attenuator 15
The optimal settings for 2 are stored in memory and applied to the microprocessor based on input control signals or based on automatic determination of signal characteristics.
【００２９】非線形信号応答特性をもつ出力増幅器は、
多段増幅器網の先行増幅器を選び、その先行増幅器にフ
ィ−ドフォワ−ド過補正を与えて出力増幅器の非線形信
号応答特性を補償することによって線形化される。An output amplifier having a non-linear signal response characteristic
The preamplifier of the multistage amplifier network is linearized by selecting the preamplifier and providing the feedforward overcorrection to compensate for the non-linear signal response of the output amplifier.
【図１】本発明の一実施態様に使用した装置の略ブロッ
ク図である。FIG. 1 is a schematic block diagram of an apparatus used in one embodiment of the present invention.
【図２】電力入力〜電力出力の伝達曲線のグラフ説明図
である。FIG. 2 is a graph illustrating a transfer curve from power input to power output.
【図３】電力入力〜電力出力の伝達曲線の別のグラフ説
明図である。FIG. 3 is another graph explanatory diagram of a transfer curve from power input to power output.
【図４】本発明の一実施態様に使用した別の装置の略ブ
ロック図である。FIG. 4 is a schematic block diagram of another device used in one embodiment of the present invention.
【図５】図４に示した装置の改良を示す略ブロック図で
ある。FIG. 5 is a schematic block diagram showing an improvement of the device shown in FIG.
ＰＡ 電力増幅器 ＩＰＡ 中間電力増幅器 １０ アンテナ ３０、４０、５６ 方向性結合器 ３２、３２´ 混成結合器 ３４ 増幅器 ３６、３６´５０、５０´ 可変遅延回路 ５２、１０４ 可変減衰器 ５４、５４´ 線形増幅器 ５８ 固定遅延回路 １０２ 固定方向性結合器 １０６ アップコンバ−タ １０８ 局部発信器 １５０ 電子可変遅延回路 １５２ 電子可変減衰器 １５４ マイクロプロセッサ PA power amplifier IPA intermediate power amplifier 10 antenna 30, 40, 56 directional coupler 32, 32 'hybrid coupler 34 amplifier 36, 36'50, 50' variable delay circuit 52, 104 variable attenuator 54, 54 'linear amplifier 58 Fixed delay circuit 102 Fixed directional coupler 106 Upconverter 108 Local oscillator 150 Electronic variable delay circuit 152 Electronic variable attenuator 154 Microprocessor
Claims (9)
の間の多段増幅器網に配置された出力増幅手段を、先行
する増幅手段にフィ−ドフォワ−ド補正を提供すること
によって線形化する方法において、 前記多段増幅器網内あって、前記出力増幅器の非線形信
号応答特性に類似する非線形信号応答特性を示す前記先
行増幅手段を選択する工程；該選択した先行増幅手段に
入力信号を印加して、該選択した先行増幅手段の非線形
信号応答特性の関数として通常前記入力信号と異なる信
号差を有する中間出力信号を発生させる工程；前記入力
信号の少なくとも一部と前記中間出力信号の少なくとも
一部を組み合わせて、前記信号差を表す誤り信号を得る
工程；前記誤り信号と前記中間出力信号を組み合わせて
補正された中間出力信号を得る工程；該補正された中間
出力信号を前記出力増幅手段に印加して出力信号を得る
工程；および前記出力増幅手段の非線形信号応答特性を
補償するのに十分な量まで過補正された該過補正中間出
力信号を提供する方向に前記誤り信号を調節する工程か
らなり；それによって前記出力増幅手段からの前記出力
信号を前記入力信号に直線的に関係させることを特徴と
する前記出力増幅手段の線形化法。An output amplifier having a non-linear signal response and located in a multi-stage amplifier network between a signal source and a load, is linearized by providing feedforward correction to the preceding amplifier. Selecting the preamplifier in the multistage amplifier network and exhibiting a non-linear signal response similar to the non-linear signal response of the output amplifier; applying an input signal to the selected preamplifier. Generating an intermediate output signal having a signal difference generally different from the input signal as a function of the non-linear signal response characteristic of the selected preamplifier; at least a portion of the input signal and at least a portion of the intermediate output signal; Combining to obtain an error signal representing the signal difference; combining the error signal and the intermediate output signal to obtain a corrected intermediate output signal; Applying the corrected intermediate output signal to the output amplifying means to obtain an output signal; and the overcorrected intermediate output signal overcorrected by an amount sufficient to compensate for a non-linear signal response characteristic of the output amplifying means. Adjusting the error signal in a direction to provide the output signal; thereby linearly relating the output signal from the output amplification means to the input signal.
記出力増幅手段よりも低い電力レベルで動作する先行増
幅手段を含み、前記先行増幅手段を選択する工程が、前
記出力増幅手段よりも低い周波数で動作する先行増幅手
段も含むことを特徴とする請求項１記載の方法。2. The method of claim 1, wherein the step of selecting the preamplifier includes a preamplifier operating at a lower power level than the output amplifier, and the step of selecting the preamplifier is lower than the output amplifier. The method of claim 1, further comprising a pre-amplifier operating at a frequency.
記出力増幅手段よりも低い電力レベルで動作する先行増
幅手段を選択する工程を含むことを特徴とする請求項２
記載の方法。3. The method of claim 2, wherein selecting the preamplifier comprises selecting a preamplifier operating at a lower power level than the output amplifier.
The described method.
増幅手段の通常動作周波数よりも高い周波数へアップコ
ンバ−トする工程を含むことを特徴とする請求項１〜請
求項３記載の方法。4. The method according to claim 1, further comprising the step of upconverting the output frequency of said preamplifier to a frequency higher than the normal operating frequency of said preamplifier.
プルを得て、その大きさを増幅し、かく増幅されたサン
プル信号を結合器に印加して該増幅されたサンプル信号
と前記中間出力信号を組み合わせる工程を含むことを特
徴とする請求項４記載の方法。5. The combining step obtains a sample of the input signal, amplifies its magnitude, and applies the amplified sample signal to a combiner to provide the amplified sample signal and the intermediate output signal. 5. The method of claim 4, comprising the step of combining.
向性結合器を使用して前記信号サンプルを得る工程を含
むことを特徴とする請求項１〜請求項５記載の方法。6. The method according to claim 1, wherein the step of sampling the input signal includes the step of obtaining the signal samples using a directional coupler.
信号を可変遅延手段へ印加する工程を含むことを特徴と
する請求項６記載の方法。7. The method of claim 6, wherein adjusting the error signal comprises applying the error signal to variable delay means.
補正中間出力信号を提供する方向に該誤り信号を変える
工程を含み、該誤り信号の大きさを変える工程が該誤り
信号を可変減衰手段へ印加する工程を含むことを特徴と
する請求項７記載の方法。8. The method of claim 1, wherein adjusting the error signal comprises changing the error signal in a direction to provide the overcorrected intermediate output signal, wherein changing the magnitude of the error signal comprises variably attenuating the error signal. The method of claim 7 including applying to the means.
号を可変遅延手段へ印加し、前記過補正中間出力信号を
提供する方向に前記誤り信号と前記中間出力信号を組み
合わせる工程を含むことを特徴とする請求項８記載の方
法。9. The method of claim 2, wherein adjusting the error signal includes applying the error signal to variable delay means and combining the error signal and the intermediate output signal in a direction to provide the overcorrected intermediate output signal. 9. The method according to claim 8, wherein:
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/803,222 US5850162A (en) | 1997-02-20 | 1997-02-20 | Linearization of an amplifier employing modified feedforward correction |
| US08/803222 | 1997-02-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10242771A true JPH10242771A (en) | 1998-09-11 |
Family
ID=25185940
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10036888A Pending JPH10242771A (en) | 1997-02-20 | 1998-02-19 | Linearization method for amplifier using improved feedforward correction |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5850162A (en) |
| EP (1) | EP0860940A3 (en) |
| JP (1) | JPH10242771A (en) |
| CN (1) | CN1195925A (en) |
| CA (1) | CA2228073A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002252564A (en) * | 2001-02-26 | 2002-09-06 | Hitachi Kokusai Electric Inc | Gain monitor device |
| KR20040011848A (en) * | 2002-07-30 | 2004-02-11 | 주식회사 싸이트론 | Feedforward linear power amplifier using distortion signal |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6549242B1 (en) * | 1997-04-04 | 2003-04-15 | Harris Corporation | Combining adjacent TV channels for transmission by a common antenna |
| SE510953C2 (en) * | 1997-11-21 | 1999-07-12 | Ericsson Telefon Ab L M | An amplifier and a method in the power amplifier |
| JP3405401B2 (en) | 1999-06-15 | 2003-05-12 | 日本電気株式会社 | Precompensated linearizer and linearizing amplifier |
| US6242978B1 (en) | 1999-06-30 | 2001-06-05 | Harris Corporation | Method and apparatus for linearizing an amplifier |
| US6356742B1 (en) * | 1999-08-30 | 2002-03-12 | Thomcast Communications, Inc. | Adaptive precorrection of signal combiners using passive hybrid junction sample cancellation |
| US6246286B1 (en) * | 1999-10-26 | 2001-06-12 | Telefonaktiebolaget Lm Ericsson | Adaptive linearization of power amplifiers |
| GB2356993A (en) * | 1999-12-03 | 2001-06-06 | Wireless Systems Int Ltd | A pre-distortion arrangement for an amplifier in which a second substantially identical amplifier is used to produce distortion components |
| US7078967B2 (en) | 1999-12-30 | 2006-07-18 | Nokia Corporation | Control of bias voltage |
| KR20020093327A (en) * | 2001-06-08 | 2002-12-16 | 주식회사 하이닉스반도체 | Feedforward linearizer in a IMT-2000 system |
| AU2001270212A1 (en) * | 2001-06-20 | 2003-07-09 | Harris Corporation | Rf transmitter employing linear and non-linear pre-correctors |
| SE0102345D0 (en) * | 2001-06-29 | 2001-06-29 | Ericsson Telefon Ab L M | Feed forward amplifying circuit |
| US6646505B2 (en) * | 2002-03-26 | 2003-11-11 | Motorola, Inc. | Power amplifier array with same type predistortion amplifier |
| GB2395077A (en) * | 2002-11-01 | 2004-05-12 | N & L Ltd | An amplifier arrangement linearised by predistortion and feedforward; adaptive bias for improved efficiency; thermal overload protection |
| AU2003297789A1 (en) * | 2002-12-09 | 2004-06-30 | Motorola, Inc. | Decision feed forward equalizer system and method |
| US6812792B2 (en) * | 2003-01-02 | 2004-11-02 | Harris Corporation | Precorrection of a nonlinear amplifier |
| US7582092B2 (en) | 2003-06-25 | 2009-09-01 | Depuy Products, Inc. | Assembly tool for modular implants and associated method |
| US7297166B2 (en) | 2003-06-25 | 2007-11-20 | Depuy Products, Inc. | Assembly tool for modular implants and associated method |
| US8998919B2 (en) | 2003-06-25 | 2015-04-07 | DePuy Synthes Products, LLC | Assembly tool for modular implants, kit and associated method |
| US7856105B2 (en) * | 2006-03-09 | 2010-12-21 | Andrew Llc | Apparatus and method for processing of amplifier linearization signals |
| US8036260B2 (en) | 2007-08-30 | 2011-10-11 | Freescale Semiconductor, Inc. | System and method for equalizing an incoming signal |
| US8556912B2 (en) | 2007-10-30 | 2013-10-15 | DePuy Synthes Products, LLC | Taper disengagement tool |
| US8518050B2 (en) | 2007-10-31 | 2013-08-27 | DePuy Synthes Products, LLC | Modular taper assembly device |
| US8054629B2 (en) | 2008-09-30 | 2011-11-08 | Intel Corporation | Microfins for cooling an ultramobile device |
| US8533921B2 (en) | 2010-06-15 | 2013-09-17 | DePuy Synthes Products, LLC | Spiral assembly tool |
| US9095452B2 (en) | 2010-09-01 | 2015-08-04 | DePuy Synthes Products, Inc. | Disassembly tool |
| EP2856976A1 (en) | 2011-04-06 | 2015-04-08 | DePuy Synthes Products, LLC | Instrument assembly for implanting a revision hip prosthesis |
| CN111064478B (en) * | 2019-12-16 | 2021-04-27 | 紫光展讯通信(惠州)有限公司 | Time delay calibration method, wireless radio frequency device and computer readable storage medium |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3471798A (en) * | 1967-12-26 | 1969-10-07 | Bell Telephone Labor Inc | Feed-forward amplifier |
| US4348642A (en) * | 1980-08-29 | 1982-09-07 | Rockwell International Corporation | Feedforward wideband amplifier |
| US4352072A (en) * | 1980-08-29 | 1982-09-28 | Rockwell International Corporation | Feedforward amplifier with enhanced stability into loads with high VSWR |
| US4453133A (en) * | 1982-04-05 | 1984-06-05 | Bell Telephone Laboratories, Incorporated | Active predistorter for linearity compensation |
| US4595882A (en) * | 1984-05-30 | 1986-06-17 | Rockwell International Corporation | Phase adjusted feedforward error correction |
| US5193224A (en) * | 1991-04-24 | 1993-03-09 | Northern Telecom Limited | Adaptive phase control for a power amplifier predistorter |
| US5570063A (en) * | 1995-05-18 | 1996-10-29 | Spectrian, Inc. | RF power amplifier with signal predistortion for improved linearity |
-
1997
- 1997-02-20 US US08/803,222 patent/US5850162A/en not_active Expired - Fee Related
-
1998
- 1998-01-28 CA CA002228073A patent/CA2228073A1/en not_active Abandoned
- 1998-02-12 EP EP98301022A patent/EP0860940A3/en not_active Withdrawn
- 1998-02-19 CN CN98104491A patent/CN1195925A/en active Pending
- 1998-02-19 JP JP10036888A patent/JPH10242771A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002252564A (en) * | 2001-02-26 | 2002-09-06 | Hitachi Kokusai Electric Inc | Gain monitor device |
| KR20040011848A (en) * | 2002-07-30 | 2004-02-11 | 주식회사 싸이트론 | Feedforward linear power amplifier using distortion signal |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0860940A2 (en) | 1998-08-26 |
| EP0860940A3 (en) | 1999-12-01 |
| US5850162A (en) | 1998-12-15 |
| CA2228073A1 (en) | 1998-08-20 |
| CN1195925A (en) | 1998-10-14 |
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